1. Field of the Invention
The present invention relates to an automatic grommeting machine for high speed, large volume insertion and setting of eyelets, grommets, etc., and their mating washers, without requiring pre-punching of a hole.
2. Description of the Background Art
Some conventional grommeting machines require the operator to manually insert the grommet or eyelet and mating washer in position before they are set by the grommeting machine. Thus, the operator must perform at least three steps, i.e, inserting a grommet or eyelet, inserting the mating washer, and placing the material in the machine, prior to setting the pieces. This process is both time consuming and inefficient. Other conventional machines also require the operator to cut or punch a hole in the material prior to setting the grommet or eyelet and mating washer. The above described grommeting machines are particularly unsuited and inefficient for factories where high speed and high volume grommet or eyelet insertion procedures are required. Further, conventional hole cutting or punching processes remove small amounts of the material which could be used more effectively, e.g., to strengthen the set, when sandwiched between the grommet and washer.
Some conventional grommeting machines employ a dual feed apparatus, such as disclosed in Stanik (U.S. Pat. No. 4,247,032). However, these machines typically require a retracting mechanism for physically moving the entire grommet and/or washer feeding structures out of the way of the piercing and setting apparatus when the grommet and/or washer are inserted and set. The retracting mechanism must move out of the way rapidly so that the grommet and washer can be inserted and set quickly without interference from the setting and inserting apparatus, yet the retracting mechanism is often cumbersome and heavy. As a result, when the retracting mechanism moves the relatively heavy grommet and/or washer feeding structures out of the way of the setting apparatus, the grommeting machine vibrates excessively, sometimes causing the grommeting machine to "walk" across the floor if the machine is not secured.